Desoldering implement

ABSTRACT

A hand held, hand operated tool is disclosed which has an outer cylindrical body and an inner, spring loaded plunger-piston assembly. The piston may be cocked and then held by a trigger mechanism in a forward position next to a nozzle or tip member. When the trigger is released, the piston flies back rearwardly drawing a sharp impulse of air into the cylindrical body through the nozzle member. A cocking shaft affixed to the plunger extends rearwardly out of the body and may be pushed forwardly into the body for each desired cocking stroke. A sheath for the cocking shaft is also carried by the body and is movable axially thereon. The rearward end of the sheath is closed and is engaged by the hand of the operator to push the cocking shaft into the cylindrical body of the implement. The cocking sheath is then returned by a second, light spring to its fully extended position, while the cocking shaft is held forwardly by the trigger mechanism. The cocking sheath provides both a handle and a protection covering for the cocking shaft. The tip element is frictionally held within the forward end of the cylindrical body and is cleaned with each cocking stroke by the passage therethrough of a cleaning shaft affixed to and extending forwardly from the piston. When the cocking shaft is urged extraordinarily forwardly, the tip is particularly thoroughly cleaned and by further pushing of the cocking plunger, the tip member is ejected as for inspection, cleaning, or replacement. A reading of the complete specification is recommended for a full understanding of the principles and features of the disclosed tool.

United States Patent [191 Fortune 5] June 25, 1974 DESOLDERING IMPLEMENTWilliam S. Fortune, 14250 Dearborn St., Panorama City, Calif.

[22] Filed: May 25, 1973 [21] Appl. No.: 364,082

[76] Inventor:

[52] US. Cl 15/341, 15/339, 15/344,

228/20 {51] Int. Cl. A471 5/02, A471 5/24 [58] Field of Search 15/341,344, 339; 228/20 [56] References Cited UNITED STATES PATENTS 12/1963Fortune 15/341 X 8/1966 Fortune 228/20 Primary Examiner-Harvey C. HomsbyAssistant ExaminerC. K. Moore Attorney, Agent, or Firm-Daniel T.Anderson drawing a sharp impulse of air into the cylindrical bodythrough the nozzle member. A cocking shaft affixed to the plungerextends rearwardly out of the body and may be pushed forwardly into thebody for each desired cocking stroke. A sheath for the cocking shaft isalso carried by the body and is movable axially thereon. The rearwardend of the sheath is closed and is engaged by the hand of the operatorto push the cocking shaft into the cylindrical body of the implement.The cocking sheath is then returned by a second, light spring to itsfully extended position, while the cocking shaft is held forwardly bythe trigger mechanism. The cocking sheath provides both a handle and aprotection covering for the cocking shaft.

The tip element is frictionally held within the forward end of thecylindrical body and is cleaned with each cocking stroke by the passagetherethrough of a cleaning shaft affixed to and extending forwardly fromthe piston. When the cocking shaft is urged extraordinarily forwardly,the tip is particularly thoroughly cleaned and by further pushing of thecocking plunger, the tip member is ejected as for inspection, cleaning,or replacement. A reading of the complete specification is recommendedfor a full understanding of the principles and features of the disclosedtool.

4 Claims, 8 Drawing Figures 1 DESOLDERING IMPLEMENT BACKGROUND OFINVENTION Field of the Invention The invention relates generally toremoving or lifting or drawing away, by air suction technique, smallquantities of particulate, liquid, or molten matter and particularly toapparatus improvements in hand held, hand operated vacuum strokecleaning devices. The present invention finds particularly usefulapplication in the field of soldering, desoldering, and rewiring inelectronic laboratories, maintenance shops, factories, or hobbyistsbenches; and although, in the case of clarity and brevity, much of thefollowing discussion and description of examples of the invention aredirected theretoward, it is expressly to be understood that theadvantages of the invention are equally well manifest in other fieldswherever and whenever substances are to be removed or cleaned from anobject such, for further example, in medical or dental fields as inremoval of foreign objects or unwanted substances from portions of thebody including the eye, ear, nose, throat, or open wound or the like.

Background of the Invention In the electrical arts as mentiondgit, isoften desired to desolder an electrical connection such as, for example,a wire wrapped terminal, a wirci to circuit board eyelet, or the like.The removal from the connection, of the molten solder without droppingor spattering it onto other portions of the equipment is generallyessential. Blowing or shaking the molten metal away is therefore not anacceptable practice; and, in combination with its high mass density, thehigh surface tension associated with the solder makes its removalparticularly difficult. Furthermore, the problem is aggravated by therequirement that the solder be removed quickly and without applicationof cooling means before the mechanical connection such as a wire-wrappedterminal may be taken apart.

Various non-portable central vacuum systems and highly portable andefficient hand held vacuum stroke tools have advanced the state of theart and have solved certain aspects of the desoldering problemsoutlined; however, the former suffer from disadvantages of cost,complexity, lack of versatility, and non-portability while the lattersuffer from some disadvantages, to a lesser extent, of cost andcomplexity, and, in some applications, undesirable recoil due to theflyback action of the piston cocking shaft-knob assembly during thevacuum stroke. Typically, in these prior art devices the cocking shaftwhich functions as a connecting rod between the piston and the cockingknob must be relatively massive to be strong enough to cock the pistonagainst a relatively strong loading spring. Also the cocking knob istypically large and soft, and therefore massive, for comfortablerepeated cocking cycles by the hand of the operator. These criteriacause the flyback mass to be relatively large compared to the thinwalledcylindrical housing body; consequently, the outer housing suffers arecoil causing a deflection of the solder inlet tip away from thelocation of the molten solder.

This recoil caused displacement is particularly intolerable in medicalapplications such as in removing foreign matter from a childs eye.

Another disadvantage of the abrupt flyback of the shaft and knob is thatthe eye of the operator during the vacuum stroke is typically disposednear thereto in a position causing risk of eye injury.

It is, accordingly, an object of the present invention to provideimproved vacuum stroke, cleaning apparatus which is not subject to theseand other disadvantages and limitations of the prior art.

It is another object to provide such apparatus which, while providingconsistently a highamplitude of impulse air flow, has no exposed flybackportion and a verylow inertia associated with the flyback portionsthereof causing a negligible deflection of the tool during its vacuumstroke.

It is another object to provide such apparatus which has a convenientlylockable and unlockable, compact, space saving configuration forshipping and storage.

It is another object to provide such apparatus which is low in cost andsimple, rugged, and reliable in its structure and performance.

It is another object to provide such apparatus which is automaticallyself-cleaning with each cocking cycle.

It is another object to provide such apparatus having readily removableand replaceable tip means particularly in medical uses for assuring theeffective sterility of the implement.

SUMMARY OF INVENTION Briefly, these and other objects are achieved inaccordance with the structural aspects of an example of the invention inwhich a hand held, hand operated vacuum stroke cleaning implement isprovided which includes a shroud body which holds a cylinder member anda cooperating piston-plunger member axially reciprocally movabletherewithin. The piston-plunger member is biased by a mainspring in adirection, hereinafter denoted rearwardly, away from the nozzle orvacuum tip end of the cylinder member.

The plunger member includes a cocking shaft extending rearwardly throughthe end of the cylinder member opposite from its tip or nozzle end. Thecocking shaft also extends rearwardly out of the shroud body and has alength to permit its use to urge the piston-plunger member fullyforwardly against its mainspring to a position contiguous to the tip ornozzle end of the cylinder member. A trigger mechanism carried by theshroud body engages the piston-plunger cocking shaft assembly and holdsit in the forward position until the trigger mechanism is releasedpermitting the piston to flyback and create a high magnitude impulse ofair flow through the tip nozzle member and into the interior of thecylinder member.

A cocking sheath, also carried by the shroud body, includes skirtportions which extend along retainer slots internally of the shroud bodyand are axially slidable therealong. The rearward, external end of thecocking sheath is effectively closed and, when the cocking sheath isinserted fully within the shroud body, the closed end engages the rearend of the cocking shaft and forces it forwardly to its cocked position.Thusly, the cocking shaft is operated, or cocked, without direct contactby the hand or finger of the operator and therefore needs no massiveknob or cushion carried thereby.

Once the cocking shaft is driven fully forward to its cocked position, acocking sheath return spring replaces the sheath to its rearward, fullyextended, or relatively fully withdrawn position. The trigger may thenbe released, when desired, for a rapid flyback of the piston and cockingshaft. Because the cocking shaft is within the fully extended cockingsheath, there is no danger or risk of injury to the operator even thoughthe cocking shaft is bare of any protective knob or cushion. The safetyand low inertia advantages of the cocking shaft cocking sheathsubcombination are accordingly manifest.

Sheath locking means are provided for holding the sheath in its fullyinserted, forward position in a compact configuration for shipping andfor bench or toolbox storage. The compact arrangement also providesadditional protection to the sheath and cocking shaft during periods ofnon-use.

Further details of these and other novel features and their operationand cooperation as well as additional objects and advantages of theinvention will become apparent and be best understood from aconsideration of the following description taken in connection with theaccompanying drawing which is provided by way of illustrative exampleonly.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of anexample of a vacuum stroke cleaning implement constructed in accordancewith the principles of the present invention, the implement beingillustrated in an uncocked or unloaded configuration;

FIG.,2 is a similar view partially broken away to reveal interior detailof portions of the major elements of the instrument;

FIG. 3 is a longitudinal sectional view of the structure of FIG. 2 takenalong the section reference lines 3-3 thereof;

FIG. 4 is a plan view of the apparatus of FIG. 1 illustrated during thecocking cycle;

FIG. 5 is an exploded view of that portion of the structure of FIG. 2indicated by the reference numerals 5-5 thereof;

FIG. 6 is a longitudinal sectional view of the trigger portion of FIG. 3taken along the section reference lines 6-6 thereof;

FIG. 7 is a plan view of the structure of FIG. 1 shown in a storageconfiguration; and

FIG. 8 is a plan view like that of FIG. 4 in which a tip ejectionoperation is illustrated.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT With specific reference nowto the figures in detail; it is stressed that the particulars shown areby way of example and for purposes of illustrative discussion only andare presented in the cause of providing what is believed to be the mostuseful and readily understood description of the principles andstructural concepts of the invention. In this regard, no attempt is madeto show structural details of the apparatus in more detail than isnecessary for a fundamental understanding of the invention. Thedescription taken with the drawing will make it apparent to thoseskilled in the mechanical arts how the several forms of the inventionmay be embodied in practice. Specifically, the detailed showing is notto be taken as a limitation upon the scope of the invention which isdefined by the appended claims forming, along with the drawing, a partof this specification.

In FIG. 1, the example of the vacuum stroke cleaning implement 10illustrated includes a cylindrical body member 2 having an open forwardend 14 and a substantially closed, plunger shaft journal supporting rearend 16. A trigger assembly 18 which cooperates with the plunger shaft iscarried by the rear end 16 of the body member 12.

A vacuum cylinder 20 is carried by and partially enclosed within thebody member 12. In this example, the cylinder 20 is molded of a rigidtransparent plastic for visibility therewithin as for inspectionpurposes. A tip and nozzle assembly 22, 24 is removably carried by theforward end 26 of the cylinder 20.

A cocking sheath 28 is also carried by the body member 12 and has a pairof retainer tongue side members 30, 32 which extend forwardly, axiallyslidingly into retaining channels (shown in subsequent figures) of thebody member 12. The rear end portion 34 of the cocking sheath isessentially closed and is formed to include a cocking shaft engaginganvil surface 36. A cocking sheath return spring 38 is axiallycompressively retained within the cocking sheath between the end portion34 and the rear end 16 of the body member 12. Each of the retainertongue side members 30, 32 is provided with a latching aperture 40 whichcooperates with a latching lug (shown in subsequent figures) carried onthe inner surface of each of a pair of flexible locking tabs 44 carriedby the rear end of the body member 12. The latching lugs may be insertedinto the latching apertures 40 when desired to retain the cocking sheathin a protective, compact relation with the body member 12 as forshipping or toll box storage of the tool, the cocking sheath beingotherwise returned to its axially extended position, as shown, by thereturn spring 38. i

In FIG. 2 further details of the major elements of the tool 10 are shownin a partially cut-away version of the previous figure. For example, theentire length of the transparent cylinder 20 is exposed and it may benoted that the cylinder is a simple, hollow and thin walled, rightcircular cylinder open at both ends, the only irregularity being a pairof locking shoulders 46 which slide along guiding channels, not shown,formed in the inner surface of the body member 12, and achieve a bayonettype of locking engagement with mating structure, shown in subsequentfigures, of the body member 12 and disposed at the rear end 16 thereof.

Also exposed in FIG. 2 is the forward end of one of the retainer tonguemembers 32. The cocking sheath 28 is held to the body member 12 by aretainer lug 48 molded integrally with the forward tip end of each ofthe tongue members. The retainer lugs slide axially along respectivecooperative grooves formed in the inner surface of the body member 12and are held from ejection to the rear by a stopping edge 50 on the bodymember 12. The latching lug portion 52 of the flexible latching tab 44is also shown.

The piston-plunger assembly 54 is shown and includes a piston 56 andpiston o-ring 58 disposed in vacuum pump relation within the cylinder20. A tip cleaning rod 60 is carried by the plunger assembly and extendsforwardly therefrom into the nozzle 20 when the piston is pushed intoits cocked position. A relatively stiff vacuum stroke or recoil spring62 is connected axially in tension between the piston 56 and the rearend portion 16 of the body member 12.

In FIG. 3, the retaining, guide channels 64, 66 in the body member 12for the retaining lugs 48 of the tongue members 30, 32 are shown. Theretaining and guiding channels are molded in the inner surface of thebody member 12 and may extend essentially for the entire length thereof.Also to be noted from this view is the sheath-like nature of the bodymember 12 with respect to the cylinder 20. The annular spacing 67between the two cylindrical elements serves two particularly usefulfunctions: first, the space provides a guideway for the axially slidabletongue, side members 30, 32 of the cocking element 28; and, secondly,the space serves as a baffle for the output of air from the vacuum pumpstroke of the piston plunger 54. Exhaust air from the cylinder isreleased into the annular space 67 through an exhaust aperture 68 nearthe rear of the cylinder 20. From there, the air is forced abruptlyforwardly along the outer surface of the cylinder and finally into thesurrounding atmosphere about the tip of the instrument. The bafflingtends to cause the precipitation within the annular space 67 of tinybits of solder or droplets of lubricant or other foreign matter. Thusdelicate electronic circuitry and the like is protected fromcontamination or other such damage. As is apparent from later figures,the surfaces bounding the annular space may be readily cleaned of thecollected foreign matter.

With reference to the piston-plunger assembly 54, it may be understoodfrom this view that the cleaning rod 60 is a forwardly directedextension of a plunger mounting rod 70 upon which the piston 56 ismounted and which has a rearwardly extending cocking rod 72, the end 74of which is engaged by the anvil surface 36 of the cocking sheath 28suring the manual cocking stroke of the piston assembly. lnlaid withinor otherwise affixed to the outer surface of the rear 34 of the cockingsheath may be a soft rubber bumper element 75 for added gripping whenthe tool is cocked by engaging the end 34 against the workbench andpushing the cocking sheath into the body member 12.

The cocking or vacuum stroke spring 62 is suspended over the plungermounting rod 70 in tension between its hook end 76 affixed to the rearend portion 16 of the body member I2 and its forward hook end 78 affixedto the rear of the piston 56. When the piston assembly is pushedforward, in its cocking stroke, against the tension of the cockingspring 62, the trigger assembly engages the cocking shoulder 80 of thecocking plunger 72 and holds the piston assembly in its forwarddisposition, as shown in FIG. 4 until the trigger 82 is pressed torelease it and permit it to fly back to its rear, uncocked dispositionat the rear of the body member 12.

Also to be noted in FIG. 4 is that in the cocked mode, the tip cleaningrod extension 60 is automatically inserted into the bore 83 of thenozzle 22 thusly to clean it of any foreign material deposited there asduring the previous vacuum stroke In FIG. 5, the assembly-disassembly ofcylinder 20 and the body member 12 are illustrated. The bayonet typelocking shoulders 46 slide axially into guide slots 84 formed, asindicated, in the inner surface of the body member 12. During assemblyas, for example, after cleaning and lubricating the cylinder 20, thelegend push in" on the cylinder 20 is aligned with the legend in on thebarrel of the body member 12; this aligns the locking shoulders 46 withthe guide slots 84. Full insertion is then made and the cylinder isrotated a few degrees clockwise to lock the assembly by bayonet typeengagement with the dog-leg portions 86 of the rear end of the slots 84.

Also illustrated in FIG. 5 and to be distinguished from the cylinderguide slots 84 are the'guide slots 64, 66 for the tongue extensions 30,32 of the cocking sheath 28.

The exhaust port 68 in the side of the cylinder 20 is shown to bedisposed, in this example in line with one of the slots 84 whereby theexhaust air from the vacuum stroke is further confined to flowtherealong and be controlled as it leaves the vicinity of the tool. Itshould be noted that the exhaust port deliberately is not disposed atthe extreme rear end of the cylinder 20. As shown most clearly in FIG.3, the port is forward of the piston ring 58, in the uncocked mode,whereby during the flyback stroke of the piston, a cushion of air istrapped behind the piston to decelerate it gradually and therebyminimize the impact impulse when the spring would otherwise slam againstits coiled self and the rear of the body member 12. The cushioningeffect minimizes the recoil effect and, consequently, the displacementof the nozzle 22 away from its desired point of application on the workpiece.

The trigger mechanism 18 illustrated in FIG. 6 includes a housing formedintegrally with the rear portion 16 of the body member 12. A triggerplunger 88 is retained in the bore 89 of the housing by virtue of theplunger mounting rod 72 passing through an opening 90 therein. Theopening 90 has a retaining lip 92 which engages the retaining shoulderon the rod 70-72 when the latter is pushed forwardly during the cockingstrode. The lip 92 edge may be reinforced by a metal disc 94 emplaced,as shown, on the lower surface of the opening 90. The retaining edge 92of the trigger plunger 88 is held in engagement with the shoulder 80 bya compression spring 96 retained between the bottom of the bore 89 andthe bottom of the trigger plunger 88. When the trigger plunger isdepressed, the spring 96 is further compressed and the edge or retaininglip 92 is displaced away from its retaining contact with the shoulder80. This then permits the flyback of the piston plunger assembly.

When it is desired to displace the rod 70-72 further forwardly as forthorough cleaning of the bore 83 of the tip 22 or for ejecting the tipelement 24 by pushing it with the piston 56 (all as shown in FIG. 8),the ratchet action of the trigger retaining lip 92 permits furtherforward movement of the rod without permitting inadvertent flyback ofthe piston assembly; since, when released, the retaining shoulder 80will again be held by the lip 92 until the trigger plunger 88 isdeliberately depressed.

Referring to FIG. 7, the flexible latching tabs 44 on the body member 12are shown with their latching lug portions 52 engaged within thelatching apertures 40, not shown, of the tongue members. The latchinglug portions 52 are retained within the apertures 40 by the compressionof cocking sheath return spring 38. When it is desired to release thecocking sheath from this storage or shipping configuration, one needmerely push the cocking sheath forwardly slightly; this permits theresilient tabs 44 to pop outwardly and automatically disengage thelatching lugs 52 from the aperture 40. In

turn, then, the cocking sheath 28 is returned by the spring 38 to itsfully extended position as shown in FIG. 8.

There has thus been disclosed and described an example of a vacuumstroke cleaning implement which exhibits the advantages and achieves theobjects set forth hereinabove. Of particular note are the advantages oflow recoil due to the low mass of the piston assembly and the safety tothe operator due to the cocking plunger being sheathed during theflyback stroke. The packing-locking features of the cocking sheath arealso of special note because of the protection afforded the instrumentand the more compact configuration of the tool for storage.

What is claimed is: 1. Vacuum stroke cleaning implement comprising: anelongate body member having a rear, journal end, cylinder means disposedat least partially within said body member; piston means carried by saidcylinder means in air pump cooperation relation therewith; piston shaftmeans affixed to said piston means and having a rear, engaging endportion extending rearwardly therefrom through said journal end of saidbody member; cocking spring means carried by said body member and beingof the character to urge said piston means rearwardly in said cylindermeans; first trigger-latch means carried by said body member and beingactuable from the exterior thereof; second trigger-latch means carriedby said piston shaft means and being cooperative with said firsttrigger-latch means to retain said piston shaft means in a forwarddisposition against said urging of said cocking spring means untilexternal actuation of said first trigger-latch means, thereuponproviding rearward flyback of said piston means in said cylinder means;cocking sheath means carried by said body member and being axiallyslidable with respect thereto and having a rear, substantially closedend portion disposed to engage said rear, engaging end portion of saidpiston shaft means for pushing it forwardly along said cylinder meansagainst said urging of said cocking spring, cocking sheath return springmeans disposed compressively between said cocking sheath and said bodymember for returning said cocking sheath rearwardly and out ofengagement with said piston shaft'means; said cocking sheath includingretainer-guide portion extending forwardly in engagement with said bodymember;

said body member including an external shroud portion extendingforwardly from said rear, journal end over at least a portion of saidcylinder means and defining therebetween cocking sheath retaining slotmeans for axially slidably receiving and retaining said retainer-guideportion of said cocking sheath means.

2. The invention according to claim 1 which further includes a tip andnozzle member carried by the forward end portion of said cylinder means;and

tip cleaning means including a cleaning rod element carried by andextending forwardly from said piston means and insertable within saidnozzle member when said piston means is pushed forwardly against theinfluence of said cocking spring means.

3. The invention according to claim I in which said cylinder means is ofthe character to be removably inserted within said body member andincludes first cylinder locking means and in which said body memberincludes second cylinder locking means for cooperatively engaging saidfirst cylinder locking means to lock said cylinder means within saidbody member.

4. The invention according to claim 1 in which said retainer-guideportion of said cocking sheath includes at least one elongated tonguemember.

1. Vacuum stroke cleaning implement comprising: an elongate body memberhaving a rear, journal end, cylinder means disposed at least partiallywithin said body member; piston means carried by said cylinder means inair pump cooperation relation therewith; piston shaft means affixed tosaid piston means and having a rear, engaging end portion extendingrearwardly therefrom through said journal end of said body member;cocking spring means carried by said body member and being of thecharacter to urge said piston means rearwardly in said cylinder means;first trigger-latch means carried by said body member and being actuablefrom the exterior thereof; second trigger-latch means carried by saidpiston shaft means and being cooperative with said first trigger-latchmeans to retain said piston shaft means in a forward disposition againstsaid urging of said cocking spring means until external actuation ofsaid first trigger-latch means, thereupon providing rearward flyback ofsaid piston means in said cylinder means; cocking sheath means carriedby said body member and being axially slidable with respect thereto andhaving a rear, substantially closed end portion disposed to engage saidrear, engaging end portion of said piston shaft means for pushing itforwardlY along said cylinder means against said urging of said cockingspring, cocking sheath return spring means disposed compressivelybetween said cocking sheath and said body member for returning saidcocking sheath rearwardly and out of engagement with said piston shaftmeans; said cocking sheath including retainer-guide portion extendingforwardly in engagement with said body member; said body memberincluding an external shroud portion extending forwardly from said rear,journal end over at least a portion of said cylinder means and definingtherebetween cocking sheath retaining slot means for axially slidablyreceiving and retaining said retainer-guide portion of said cockingsheath means.
 2. The invention according to claim 1 which furtherincludes a tip and nozzle member carried by the forward end portion ofsaid cylinder means; and tip cleaning means including a cleaning rodelement carried by and extending forwardly from said piston means andinsertable within said nozzle member when said piston means is pushedforwardly against the influence of said cocking spring means.
 3. Theinvention according to claim 1 in which said cylinder means is of thecharacter to be removably inserted within said body member and includesfirst cylinder locking means and in which said body member includessecond cylinder locking means for cooperatively engaging said firstcylinder locking means to lock said cylinder means within said bodymember.
 4. The invention according to claim 1 in which saidretainer-guide portion of said cocking sheath includes at least oneelongated tongue member.